How can anybody say that there are no differences?? It's called VARIANT for a reason.
The new Shizuo looks more "bishounen", more like the DURARARA x2 season.
He looks younger and very sexy.

Both are awesome because Shizuo is always awesome.
It's worth to have 'em both if you like the character, and it's a GREAT opportunity to all of us who missed the first one.
So please, STOP blaming Alter for remaking them: I own Aoba from Dramatical Murder, and yes, I wanted a new figure from this series but they did a remake. Why? Because people missed the first press. I was happy for all the people who went crazy for missing their favourite character's preorder.
If you already own the first Shizuo FINE, BE HAPPY and stop. Everybody would like a Shinra figure, but we can't do anything about it.
Alter went for those who sell the most and are obviously sold out. They could have done a simple re-sell without any changes, but they tried to make them look a bit different to make everybody a little bit happy.